Developing a procurement path determination chart SEM-based approach

The choice of an appropriate procurement system is crucial to construction project success. Procurement selection is largely based on path determination charts, with at least eight key criteria needing to be weighted by decision-makers. Including certain criteria whilst ignoring client-borne transaction costs (TCs) resulting from environmental uncertainties simplifies this process. TCs are ‘unseen’ costs associated with pre- and post-contract work. The effects of uncertainties in the transaction environment and procurement systems on TCs are investigated, comparing the traditional and design-build procurement systems. A cross-sectional sample approach was deployed, involving survey questionnaire and results verification through ‘real-world’ cases. Data was sought from construction professionals in management, design and operation of construction projects. The research participants evaluate their time spent on procurement activities using a five-point Likert scale. Hypotheses of the relations between environmental uncertainties, procurement systems, and pre- and post-contract TCs are tested using a structural equation modelling (SEM) approach. The study found that TCs account for about 46.75% and 42.88% of the daily time spent by project managers in traditional and design-build procurement systems in New Zealand respectively. The study concludes that the TC concept is a useful framework for determining objective instead of subjective opinions for procurement decisions.     

Effects of drying conditions, admixtures and specimen size on shrinkage strains

The paper presents the results of an experimental investigation on the effects of drying conditions, specimen size and presence of plasticizing admixture on the development of shrinkage strains. The measurements are taken in a harsh (50 °C and 5% R.H.) and a moderate environment (28 °C and 50% R.H.). The results include strain development at various levels of cross sections of concrete prisms. The drying conditions are found to be the dominant parameter affecting the shrinkage strain development particularly in specimens of smaller sizes. The effect of plasticizing admixture on shrinkage strains is negligible.     

Physical investigations on Ni doping ZnO thin films along with ethanol response

Journal of Materials Science: Materials in Electronics - Undoped and Ni-doped ZnO thin films were grown on glass substrates at 460 °C using the spray pyrolysis method. All samples...     

Analytical study on RC beams strengthened for flexure with externally bonded FRP reinforcement

This paper presents analytical study on reinforced concrete (RC) beams strengthened for flexure with externally bonded fiber reinforced polymer (FRP) reinforcement. A simple yet rational numerical model is developed and proposed for this purpose. The model is based on cross-sectional analysis satisfying strain compatibility and equilibrium conditions. The moment–curvature relationship can be generated for an RC beam section using an incremental strain technique. The model can also generate the load–deflection relationship of the beam with respect to its configuration, loading system, and preloading conditions. The model can predict the flexural capacity of FRP-strengthened section based on full composite action and IC debonding failure modes. This also allows for designing the FRP strengthening area according to the desired failure mode. Various IC debonding criteria were adopted in the model and compared with test results from the literature. The result of comparison indicated that the accuracy of the model is dependent on the adopted IC debonding criterion. Furthermore, the model was verified against test data related to full composite action failure mode and good agreement was found.     

Tailoring the structural,optical, dielectric,and electrical properties of PEO/PVA blend using graphene nanoplates for energy storage devices

Journal of Materials Science: Materials in Electronics - Our articles describe the casting process for producing polyvinyl alcohol (PVA)/polyethylene oxide (PEO)/graphene nanoplates (GNPTs)...     

A 3 MV tandetron facility at KFUPM

A 3 MV General lonex Tandetron accelerator has recently been tested at the nearly established Energy Resarch Laboratory at the King Fand University of Petroleum and Minerals. The accelerator features a very stable solid-state power supply which delivers about 3 MV of terminal high voltage. A beam resolution of about 400 eV was measured. Ions of a wide range of masses, ranging from hydrogen to gold, were accelerated. The configuration of this Tandetron will be described along with a discussion of the facility and research programs.     

Saudi cloud infrastructure: a security analysis

The growing demand and dependence upon cloud services have garnered an increasing level of threat to user data and security. Some of such critical web and cloud platforms have become constant targets for persistent malicious attacks that attempt to breach security protocol and access user data and information in an unauthorized manner. While some of such security compromises may result from insider data and access leaks, a substantial proportion continues to remain attributed to security flaws that may exist within the core web technologies with which such critical infrastructure and services are developed. This paper explores the direct impact and significance of security in the Software Development Life Cycle (SDLC) through a case study that covers some 70 public domain web and cloud platforms within Saudi Arabia. Additionally, the major sources of security vulnerabilities within the target platforms as well as the major factors that drive and influence them are presented and discussed through experimental evaluation. The paper reports some of the core sources of security flaws within such critical infrastructure by implementation with automated security auditing and manual static code analysis. The work also proposes some effective approaches, both automated and manual, through which security can be ensured through-out the SDLC and safeguard user data integrity within the cloud.     

Application and development of ground source heat pump technology in China

With the rapid growth of China’s construction industry, energy demand and energy saving for building heating and cooling are of great importance [1]. In the year 2019, significant achievements were made in the development and use of geothermal energy in China. By the end of 2019, the construction areas with shallow geothermal energy applied had reached around 841 million square meters in China, ranking first in the world. Among the shallow geothermal energy technologies, ground source heat pumps (GSHPs) have the advantages of energy saving, high efficiency, environmental protection, and cleanliness, and consequently, they are widely used in building HVAC applications. Consuming low electric power, the technology of GSHPs can transfer low-temperature thermal energy to high-temperature thermal energy. With this technology, reservoirs in shallow ground layers, including soil formation, aquifers or lakes, etc., can be used as the heat source for heating in winter, or as the heat sink for cooling in summer. From 2020, the development and use of geothermal energy in China is showing wide application prospects, featured by the large-scale development of shallow geothermal heating (cooling), the promotion of a commercial development mode of medium and deep geothermal heating, and the wide application of “geothermal energy +” [2].     

一种移动因特网中层次型QoS多径组播路由协议

提出了一种移动因特网中满足QoS约束的组播路由协议QoSHMM．基于“同层成环、异层构树”的原则,该协议建立一棵特殊的QoSHMM组播环树,从而在目的节点与源节点之间形成一条具有最短时延的路径和多条满足时延受限成本较小的路径．模拟结果显示。QoSHMM组播环树在平均切换延迟方面表现出了很好的性能。同时由于采用三态传输机制,该协议也具有很好的容错性．     

Preparation of highly efficient sunlight driven photodegradation of some organic pollutants and H2 evolution over rGO/FeVO4 nanocomposites

FeVO₄ and rGO/FeVO₄ nanocomposites were synthesized by one-step hydrothermal method. The structural and morphological properties of the prepared samples were investigated by XRD, TEM, EDS, XPS, FTIR, Raman, UV–Vis DRS and PL techniques. XRD, XPS and Raman techniques displayed that graphene oxide (GO) was successfully reduced to reduced graphene oxide (rGO) under hydrothermal conditions. Also, the addition of rGO enhanced the visible light absorption, oxygen vacancies, phase transformation of FeVO₄ from triclinic to monoclinic phase at high amount of rGO and reduced the band gap energy of FeVO₄. The photoactivity of the synthesis catalysts was investigated for the photodegradation of Malachite green, phenol, Methylene blue and Rhodamine B under natural sunlight. Also, the catalysts were applied in H₂ evolution from water splitting. The results showed that, the rGO amount was proven to be a crucial factor affecting the structural properties and photocatalytic performance of FeVO₄. The mineralization (TOC), photodegradation mechanism and photocatalytic reaction kinetics were discussed.